#定义变量
# age = 17
# if age >= 18:
#     print("允许进入网吧")
# print("未成年加十块")

# not
# age = 18
# if not (age < 18):
#     print("已成年")
# else:
#     print("未成年")

# not 构成条件
# employer = False #假设已经固定值
# if not employer:
#     print("本公司员工")
# else:
#     print("非本公司员工")

# age = int(input("输入用户年龄:"))
# if age >= 18:
#     print("允许进入网吧")
# else:
#     print("加钱")

# score = int(input("输入分数："))
# if score >= 90:
#     print("优")
# elif 80 <= score < 90:
#     print("良")
# elif 70 <= score < 80:
#     print("中")
# elif 60 <= score < 80:
#     print("差")
# else:
#     print("不及格")

#定义变量
#不输入就是无票、输入任意字符表示有票
# has_ticket = input("请确认是否有票：")
# if has_ticket:
#     knife_length = int(input("请输入刀的长度："))
#     if knife_length >=20:
#         print("不允许上车")
#     else:
#         print("安检通过，运行上车")
# else:
#     print("不允许进门")